Understanding success rates
The HFEA defines success rates as the proportion of embryos transferred that result in a live birth. These rates are influenced by many factors, including your age, ovarian reserve (AMH), and medical history.
Because every patient is different, no clinic can guarantee a specific outcome. Instead, the HFEA success rates give you a good indication of how a clinic and its lab perform against other clinics.
The HFEA have two measures of success: births per embryo transferred and multiple birth rate. These are all important factors to understand when choosing a fertility clinic, but what do they mean?
The term “births per embryo transferred” means the number of babies born for every embryo placed back inside the mother.
This is how we and the HFEA present our success rates.
This is different to “births per embryo transfer“, which could mean multiple embryos are placed back inside the mother.
Watch Emma Whitney’s short video below, where she explains why this is so important for patients to understand.
Multiple pregnancies are a risk when having fertility treatment, not only for the mother and babies, but also for any problems that can sometimes be lifelong.
It’s now best practice to transfer only one embryo during an embryo transfer event to reduce the chance of multiple pregnancies, which can pose serious risks to both the mother and babies.
The HFEA closely monitors all fertility clinics’ multiple birth rates to ensure they are as low as possible. It’s important when choosing a clinic that you’re aware of their multiple birth rate.
Understanding IVF Success Rates
Why we only use HFEA-verified data
Some clinics present “success rates” using their own definitions or metrics, such as pregnancy rate or live birth rate per patient, which can make them look better on paper. However, this makes it hard for fertility patients to compare clinics and creates ambiguity.
The HFEA and CMA have clear guidance on how data should be collected and reported, and this is ‘live birth rates per embryo transferred.’
By following these rules, patients get a true picture of how clinics perform.
We commit to:
- Only publishing figures verified by the HFEA
- Presenting our data exactly as the HFEA and CMA require
- Avoiding cherry-picked data or selective patient groups
- Welcoming patients of all ages and reproductive health backgrounds
A 41% chance of a having a baby at The Evewell
Based on the most recent HFEA data, our success rates put us in the top three fertility clinics in the UK.
The following data is from treatment cycles at The Evewell Harley Street (which opened in October 2018) and The Evewell West London (which opened in May 2022) from January 2022 to December 2022, against the national average for treatments performed in 2022, as reported by the HFEA (which is the most recent national average data published by the HFEA).
* vs. the national average of 28%. As published by the HFEA, in each case, per embryo transferred.
Babies born per embryo transferred 2022 at The Evewell Harley Street
Against 2022 HFEA national average
HFEA Grouped Data - Harley Street
The HFEA presents all fertility clinic data into ‘Under 38′,’ 38 and over’, and ‘All patients’ data sets. Please see the chart below for a further age breakdown, so you can see your own individual chances of success rates based on your age group.
Babies born per embryo transferred 2022 at The Evewell Harley Street
Against 2022 HFEA national average
Maximising Chances
We don’t select patients based on age or fertility history, and where appropriate, do as much as we can in the pre-transfer stage to optimise the chances of success, for example: incorporating gynaecological investigations and further tests into your treatment plan.
In addition to being highly ethical and treating every embryo with the care and respect they deserve, fertility treatment at The Evewell is both personalised and collaborative, with the entire clinical team reviewing every patient in our daily “All Hands” meetings.
Babies born per embryo transferred 2022 at The Evewell West London
Against 2022 HFEA national average
HFEA Grouped Data - West London
The HFEA presents all fertility clinic data into ‘Under 38′,’ 38 and over’, and ‘All patients’ data sets. Please see the chart below for a further age breakdown, so you can see your own individual chances of success rates based on your age group.
Babies born per embryo transferred 2022 at The Evewell West London
Against 2022 HFEA national average
Building families
We work hard to give our patients options and choices, minimising pregnancy loss and creating families, both now and in the future.
Our results for babies per frozen embryo transferred are significantly higher than the national average, thanks to the collaborative efforts of our clinical team and embryologists, who are focused on optimising every cycle and giving future family-building options to our patients.
Babies born per PGT-A screened vs. unscreened embryos transferred
The Evewell Harley Street and West London - internal data comparison
The impact of PGT-A
If you have plans for more than one child, your consultant and embryologist may discuss with you the choice of more than one egg collection and adding PGT-A into your treatment cycle, before considering an embryo transfer, to create options for when you’re ready to come back for baby number two.
Either way, you’ll benefit from an embryologist consultation and the collective experience of our entire team, before and during your cycle.
Why fair comparison matters
We believe every patient deserves the truth. That means not using our own, unverified metrics to appear better than others. We encourage all UK fertility clinics to do the same, so that when you compare, you’re looking at real, like-for-like data.
Please note that there is a limit to what success rate data can show, and we recommend that patients use them as a guide only. Multiple factors, such as personal medical history, will affect treatment outcomes. Therefore, it is important to discuss your individual chances of success with your consultant.
Information on success rates is only one factor when choosing where to seek treatment and comparing fertility clinics. The HFEA’s ‘Choose a Fertility Clinic’ function is a useful source of information. For further information, clinic success rate comparisons and advice on choosing a clinic, please see the HFEA guidance.
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